Data is collected, but not yet analyzed, from four participants carrying compound-inactivating variants in Piezo2. Piezo2 is a expressed in some somatosensory neurons and in Merkel cells. Piezo2 is essential for discriminative aspects of touch and for proprioception. Through detailed sensory testing the role of this protein can be further characterized and the related mechanosensory deficits better understood. Data will soon be collected from one participant who, following guillain-barr syndrome, has a deafferentation of large diameter myelinated afferents producing a clinical condition with lacking discriminatory touch and proprioception. Data from this participant will be compared both to data from neurologically intact individuals but also to the 4 participants carrying compound-inactivating variants in Piezo2. Combining these data sets will allow hopefully allow us to distinguish which input from large diameter myelinated afferents is dependent on piezo2 and which input is not.